chromium/src/third_party/blink/public/common/browser_interface_broker_proxy.h

// Copyright 2019 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef THIRD_PARTY_BLINK_PUBLIC_COMMON_BROWSER_INTERFACE_BROKER_PROXY_H_
#define THIRD_PARTY_BLINK_PUBLIC_COMMON_BROWSER_INTERFACE_BROKER_PROXY_H_

#include "mojo/public/cpp/bindings/generic_pending_receiver.h"
#include "mojo/public/cpp/bindings/remote.h"
#include "third_party/blink/public/common/common_export.h"
#include "third_party/blink/public/mojom/browser_interface_broker.mojom.h"

namespace blink {

// BrowserInterfaceBrokerProxy provides access to interfaces exposed by the
// browser to the renderer. It is intended to replace document- and
// worker-scoped InterfaceProvider (see crbug.com/718652).
class BLINK_COMMON_EXPORT BrowserInterfaceBrokerProxy {
 public:
  BrowserInterfaceBrokerProxy() = default;
  void Bind(mojo::PendingRemote<blink::mojom::BrowserInterfaceBroker> broker,
            scoped_refptr<base::SingleThreadTaskRunner> task_runner);
  mojo::PendingReceiver<blink::mojom::BrowserInterfaceBroker> Reset(
      scoped_refptr<base::SingleThreadTaskRunner> task_runner);

  // Asks the browser to bind the given receiver. If a non-null testing override
  // was set by |SetBinderForTesting()|, the request will be intercepted by that
  // binder instead of going to the browser.
  void GetInterface(mojo::GenericPendingReceiver) const;

  // TODO(crbug.com/718652): Add a presubmit check for C++ call sites
  void GetInterface(const std::string& name,
                    mojo::ScopedMessagePipeHandle pipe) const;

  bool is_bound() const;

  // Overrides how the named interface is bound, rather than sending its
  // receivers to the browser. If |binder| is null, any registered override
  // for the interface is cancelled.
  //
  // Returns |true| if the new binder was successfully set, or |false| if the
  // binder was non-null and an existing binder was already registered for the
  // named interface.
  bool SetBinderForTesting(
      const std::string& name,
      base::RepeatingCallback<void(mojo::ScopedMessagePipeHandle)> binder)
      const;

 private:
  mojo::Remote<blink::mojom::BrowserInterfaceBroker> broker_;

  using BinderMap =
      std::map<std::string,
               base::RepeatingCallback<void(mojo::ScopedMessagePipeHandle)>>;
  mutable BinderMap binder_map_for_testing_;

  DISALLOW_COPY_AND_ASSIGN(BrowserInterfaceBrokerProxy);
};

// Returns an instance of BrowserInterfaceBrokerProxy that is safe to use but is
// not connected to anything.
BLINK_COMMON_EXPORT BrowserInterfaceBrokerProxy&
GetEmptyBrowserInterfaceBroker();

}  // namespace blink

#endif  // THIRD_PARTY_BLINK_PUBLIC_COMMON_BROWSER_INTERFACE_BROKER_PROXY_H_